Neonicotinoid insecticides represent an important advancement in agricultural technology that has helped American farmers increase productivity and improve cost competitiveness.
Most scientists and bee experts agree that declining bee health is a result of multiple factors, including parasites, diseases, inadequate nutrition, weather and hive-management practices. Large, multifactorial studies conducted in Europe and North America show that poor bee health correlates well with the presence of Varroa mite and bee diseases but not with exposure to agrochemicals.
Comprehensive reviews of studies and databases comprising 15 years of research have been published by a diverse group of researchers and directly challenge claims against neonicotinoids as a significant cause of colony decline. Two recent examples authoritatively challenge unsubstantiated claims against neonicotinoids as a cause of honeybee decline. In its recent 92-page report, the Australian Pesticides and Veterinary Medicines Authority examined the impact of that country’s extensive use of neonicotinoids, concluding, “the introduction of the neonicotinoids has led to an overall reduction in the risks to the agricultural environment from the application of insecticides,” and noted, “Australian honeybee populations are not in decline, despite the increased use of this group of insecticides in agriculture and horticulture since the mid-1990s.” A review by Fairbrother et al. (2014) criticized the overreliance of laboratory studies in evaluating risk, noting, “Assessing risks only under worst-case conditions with individual honeybees, divorced from properties provided by colony interactions, serves only to understand potential mechanisms of action of different chemicals but not their actual risks.” When considering the extensive body of existing research, the authors concluded that “it is not reasonable, therefore, to conclude that crop-applied pesticides in general, or neonicotinoids in particular, are a major risk factor for honeybee colonies.”
In the European Union, in contrast with a reliance on the robust, science-based approach being followed elsewhere, the EU Commission put a regulation in place on May 25, 2013, implementing a ban on certain uses of some neonicotinoids (thiamethoxam, clothianidin, imidacloprid). In preparing its recommendation to suspend neonicotinoids, the European Commission relied on a risk assessment prepared by the European Food Safety Authority (EFSA) that used a new risk-assessment methodology that had not been validated, or approved by any regulatory body in any country. These new guidelines overly rely on worst-case-exposure scenarios in making policy decisions and ignore existing, realistic, higher-tiered field tests, which support the continued use of neonicotinoids in agriculture. This is a disturbing example of using selective science and the precautionary principle applied to its most extreme.
By way of contrast, on July 17, 2012, EPA affirmed the validity of the continued registration of clothianidin based on the complete database, noting that “[the Agency] is not aware of any data that reasonably demonstrates that bee colonies are subject to elevated losses due to chronic exposure to this pesticide.”
In conclusion, neonicotinoid insecticides represent an important advancement in agricultural technology that has helped American farmers increase productivity and improve cost competitiveness. These products provide clear performance and environmental advantages over the older chemistries they replaced. The crop protection industry strongly endorses ongoing research and meaningful stewardship measures, including the adoption of best management practices, to reduce bees’ potential exposure to crop protection products. Although protecting honeybees from unintended exposure to pesticides is a commitment all agricultural stakeholders share, this will have little practical consequence unless we address the much broader and more significant threats to colony health.